New host Nish Kumar presents a celebrity Christmas special, joined by regular judge Matthew Ashton and Amy Corbett from the US version of the show. The three teams are Taskmaster's Alex Horne and Sophie Duker, Sophie Ellis-Bextor and her two sons, and Scarlett Moffatt with her dad and sister. They must construct a wearable Lego Christmas jumper that can survive star jumps and the magical interior of a snowglobe.

Six young builders from previous shows team up with celebrities to do battle in a range of festive challenges, including Rob Beckett, Warwick Davis, Joel Dommett and Alice Perrin

The four teams build a walking-talking robo-pet. There is also a Master Build using as many as half a million bricks. But who will be crowned the winner for 2018? With guest judge Sue Perkins.

It's the semi-final. The teams create a bust of comedian Johnny Vegas. Can they capture the essence of Johnny in plastic bricks? They also build a life-size arcade game.

Melvin Odoom welcomes the six remaining teams back to the Build Room. Their first challenge is to build a land and sea animal hybrid. Which team will create the wackiest creature? The teams' next challenge is the biggest yet. So big, in fact, the teams have to head off to a real life golf course to demonstrate their life-size crazy golf holes - complete with putter. Comedian and Lego superfan Chris Ramsey tees off as this episode's celebrity guest judge, joining regulars Matthew Ashton and Fran Scott to decide which teams will make it through to the semi finals.

The teams do battle in a drop test to see which model gets smashed up the best. They also build a memorable scene from history. Joining the judges is comedian Paddy McGuinness.

The teams compete to construct a skyscraper and a metre-long bridge that will withstand a weighted dumper truck . This episode's guest is comedian Rob Beckett.